Properties of Carbon. 205 



wonderful adaptations in the nature of this element 

 itself, and in its chemical relations to the other ele- 

 ments, to meet his wanfs ; since, when buried under 

 different conditions, it gives rise not only to coal, 

 but to so many kinds of coal, each one fitted for a 

 .^pecial use. 



Another remarkable characteristic of carbon is 

 its indestructibility, when in the form of coal, by all 

 ordinary agencies. Neither water, nor the oxvgen 

 of the air, has power to oxidi/e it at ordinary 

 temperatures. It defies such agencies for thousands 

 of years. But when raised to a red heat, it not 

 only unites rapidly with oxygen, but under proper 

 conditions easily secured, the process is self-sup- 

 porting. Its heat is of sufficient intensity to melt 

 all metals on the -lobe that occur as oxides, and by 

 its heat and affinity for oxygen, to reduce them 

 from oxides to the metallic state. 



We hardly need to show how unfitted it would be 

 for its most important uses were it either a liquid or 

 gas, or were it possible with furnace-heat to melt it. 

 In smelting, it can be mingled with the ore in large 

 or small pieces. Intense heat only increases its 

 affinity for the oxygen of the air and of the ore. It 

 remains solid, and firmly keeps its place, even while 

 the melted iron flows through it. The portion that 

 consumes instantly takes the form of gas, and is 

 swept out by the heated nitrogen, thus keeping the 

 products of the furnace pure and the surface of the 

 coal constantly free for increased oxidization. If 

 man was made to use fire, he must have two just 



